Last Night's TV: The Perfect Suit/BBC4<br />Afghanistan: the Unknown Country/BBC2

Ah... the great and irremediable truths of life. Here's one. Fine tailoring is forgiving to the figure in a way that tight jeans are not. Or, as the designer Antony Price more tartly puts it, while a good suit can conceal your shortcomings "if you've got a terrible arse it will be a terrible arse covered in denim". It was Price who made the suits for Bryan Ferry and Duran Duran, rescuing the outfit from the rare and almost unprecedented slough of unfashionability into which it briefly dropped in the Seventies (when the Osmonds wore suits with lapels like the deck of an aircraft carrier), and you could even argue that he was a kind of tailoring John the Baptist, paving the way for Paul Smith, who followed him both in high-street history and also in Alastair Sooke's film The Perfect Suit. I would recommend a little splash of Paul Smith to anyone making a documentary about fashion, because he refreshes almost anything he touches, and he arrived just at the right time here, when the film was hitting that difficult point when you began to wonder whether it really needed to be an hour long.

Perhaps I'm just getting short-winded these days though, because Sooke's film was a generally engaging affair, presented by someone with a genuine ease in front of the camera. And this was explicitly a beginner's guide to the subject, offered up by someone who only bought his first suit when he was getting married and didn't seem to have worn it since. He'd started well, too, by visiting Charlie Allen in Islington and getting a crash course in the hundreds of small decisions which go into a bespoke suit. "You're an illusionist," he exclaimed, as Allen explained how a deep pocket flap could reduce the length of the body. "That's what tailors should be called," replied Allen contentedly. A Topshop stylist then successfully transformed Sooke into Hoxton nitwit before our very eyes, with the help of an overtight suit and an ill-advised foulard.

Sooke looked much better in a frock coat (why can't the frock coat make a comeback soon?) and pretty passable in the Edwardian tweed that eventually succeeded it. This was one of Keir Hardie's legacies, apparently, his radical arrival in Parliament in a lounge suit helping to accelerate a trend away from the Victorian formalities that had prevailed until then. Bizarrely, his choice of the three-piece as an insurrectionary weapon was shared with the Duke of Windsor, who boldly questioned the stuffy rigidity of the monarchy by wearing a series of plaids that could induce epilepsy in an elephant. "He just had exquisite taste in everything," warbled a Savile Row admirer of the Duke – apparently indifferent to the fact that his hero's taste in German dictators later came to be seen as decidedly vulgar. That's the point of an hour-long programme about clothing, though – it's virtually impossible to get all the way through it without bumping into a dandy who can't tell the difference between style and substance.

Sooke's innocent-abroad approach sometimes grated just a little, as when he visited a Hungarian plant that supplies British labels with their off-the-peg suits: "I was imagining one enormous machine – you just put cloth in at one end and magic suits come out the other end," he said, before helpfully filling us in on his findings: "Of course it's not like that." And his eventual conclusions – that the suit now means many different things to many different men – seemed to offer meagre returns on all that travelling. But it still made an enjoyable case for the suit as a modern form of armour. Perhaps it's time for the first bespoke. With a four-button cuff, frog pockets and a shawl lapel, I think.

Governor Atta, aka "The King of the North", was wearing a suit in Afghanistan: the Unknown Country, which in this context meant something like, 'Yes, I used to be a warlord but I'm a businessman now – and if you want a substantial contract anywhere round here you'd better make sure I really like the deal." Atta was one of the high-level contacts Lyse Doucet revisited in a programme in which she promised she was "going on a journey to take you beyond the headlines". Start with that many clichés, I thought, and you'd better deliver – but she did, in her strangely chewy Canadian accent. In fact, she came across as both likeable and admirable, committed enough to the country she'd reported on for many years to have learnt the language to an impressive degree of fluency.

She seemed to have friends everywhere, though having friends in Afghanistan is no guarantee of safety since their enemies may well want to kill you. In Kandahar her armed escort was provided by a very big fish indeed, Ahmed Wali Karzai, half-brother of the president – and Doucet was bold enough to confront him with accusations of corruption and double-dealing while sitting next to him tucking into a lamb pilaff. "I'm a little off the media," he'd said at the beginning of the meal – and to her credit, she'd done nothing to soften his mood by the end of it. Most poignantly she visited Bamiyan, where a heartbreakingly hopeful local man had opened a tourism office. He took her skiing (the ski-lift was a donkey) and then to the giant scars left behind after the Taliban had destroyed Bamiyan's only significant tourist attraction, two giant stone buddhas carved into the cliffs. So far he'd only had two real tourists pass through – but he still dreamt of a better world.